Micro-seismic Event Detection of Hot Dry Rock based on the Gated Recurrent Unit Model and a Support Vector Machine

Micro-seismic monitoring is one of the most critical technologies that guide hydraulic fracturing in hot dry rock resource development. Micro-seismic monitoring requires high precision detection of micro-seismic events with a low signal-to-noise ratio. Because of this requirement, we propose a recurrent neural network model named gated recurrent unit and support vector machine(GRU;VM). The proposed model ensures high accuracy while reducing the parameter number and hardware requirement in the training process. Since micro-seismic events in hot dry rock produce large wave amplitudes and strong vibrations, it is difficult to reverse the onset of each individual event. In this study, we utilize a support vector machine(SVM) as a classifier to improve the micro-seismic event detection accuracy. To validate the methodology, we compare the simulation results of the short-term-average to the long-term-average(STA/LTA) method with GRU;VM method by using hot dry rock micro-seismic event data in Qinghai Province, China. Our proposed method has an accuracy of about 95% for identifying micro-seismic events with low signal-to-noise ratios. By ignoring smaller micro-seismic events, the detection procedure can be processed more efficiently, which is able to provide a real-time observation on the types of hydraulic fracturing in the reservoirs.

Unit 1 of Ling’ao Nuclear Power Plant phase II underwent hot functional test successfully

On February 25, the Unit 1 of Ling’ao Nuclear Power Plant phase II underwent a 41-day-long hot functional test successfully with its major systems satisfying the requirements for

Complete Mill Simulation of the Rolling Process of 1660 mm Hot Strip Continuous Mills

The three-dimensional plastic deformations of strip are analyzed using the stream surface strip element method, the elastic deformations of rolls are analyzed using the influence coefficient method, the analyzing and computing model of shape and crown of 4-high mill was established by combining them, and the rolling process of 1660 mm hot strip continuous mills was simulated. The simulated results tally well with the experimental results. The modei and the method for simulation of shape analysis and control of hot strip mills were provided.

Assessment of Fatigue Strength of An Offshore Floating Production and Storage Unit

The procedure of assessment of structural fatigue strength of an offshore floating production and storage and offloading unit (FPSO) in this paper. The emphasis is placed on the long-term prediction of wave induced loading, the refined finite element model for hot spot stress calculation, the combination of stress components, and fatigue damage assessment based on S-N curve.

Thermodynamic Simulation of CCP in Air-Cooled Heat Pump Unit with HFCs and CO₂Trans-Critical

The exergy analysis and finite time thermodynamic methods had been employed to analyze the compound condensation process (CCP). It was based on the air-cooling heat pump unit. The cooling capacity of the chiller unit is about 1 kW, and the work refrigerant is R22/R407C/R410A/CO2. The MATLAB/SIMULINK software was employed to build the simulation model. The thermodynamic simulation model is significant for the optimization of parameters of the unit, such as condensation and evaporation temperature and mass flow of the sanitary hot water and size of hot water storage tank. The COP of the CCP of R410A system is about 3% - 5% higher than the CCP of the R22 system, while CCP of the R407C system is a little lower than the CCP of R22 system. And the CCP of CO2 trans-critical system has advantage in the hot supply mode. The simulation method provided a theoretical reference for developing the production of CCP with substitute refrigerant R407C/R410A/CO2.

Stream Surface Strip Element Method and Simulation of Three-Dimensional Deformation of Continuous Hot Rolled Strip

A new method,the stream surface strip element method,for simulating the three-dimensional deformation of plate and strip rolling process was proposed.The rolling deformation zone was divided into a number of stream surface(curved surface)strip elements along metal flow traces,and the stream surface strip elements were mapped into the corresponding plane strip elements for analysis and computation.The longitudinal distributions of the lateral displacement and the altitudinal displacement of metal were respectively constructed to be a quartic curve and a quadratic curve,of which the lateral distributions were expressed as the third-power spline function,and the altitudinal distributions were fitted in the quadratic curve.From the flow theory of plastic mechanics,the mathematical models of the three-dimensional deformations and stresses of the deformation zone were constructed.Compared with the streamline strip element method proposed by the first author of this paper,the stream surface strip element method takes into account the uneven distributions of stresses and deformations along altitudinal direction,and realizes the precise three-dimensional analysis and computation.The simulation example of continuous hot rolled strip indicates that the method and the model accord with facts and provide a new reliable engineering-computation method for the three-dimensional mechanics simulation of plate and strip rolling process.

高精主轴装配工艺设计与测试

主轴单元是数控机床的重要功能部件之一,其装配质量将影响机床的加工精度及稳定性等性能指标。为满足数控机床高精高速的实际需求,降低机床主轴单元的故障率,对主轴运转噪声大、轴承温升过高、切削工件表面有振纹等常见故障现象进行研究。结合上述故障产生的原因,分别对相关装配过程作了梳理和总结,如:影响主轴运转噪声的主轴组件动平衡校核工序;影响轴承温升及切削性能的选择配置主轴轴承等工序。通过对主轴单元的温升测试及抗振性切削测试,从而验证了所述装配工艺的正确性和合理性,具有一定的借鉴价值。

炉外热风冲天炉的热风单元与除尘风量设计

介绍了炉外热风冲天炉除尘系统处理风量的计算方法,分析了炉外热风冲天炉的除尘系统处理风量对热风单元工作的影响,并通过列举的国内外有关冲天炉的除尘风量参考数据,得出以下结论:(1)炉外热风冲天炉除尘系统的处理风量与热风单元的工作存在着密切的关系,且该类炉首先需要准确计算冲天炉除尘系统的处理风量;(2)需要选用风量和风压合适的风机,且风机风量不能过大;(3)除尘系统的风量调节必须以风机进口阀调节为主,不能用变频器对除尘风量进行大幅度调节。

论电镍出装机组的设计理念与技术路线

论述了当前研发电镍出装机组需考虑的五个新理念,分别是智能化理念、倒置烫洗理念、压耳加工理念、节能环保理念、机组与酸雾隔离理念。并以此说明,目前电镍出装机组的研发,不可以再沿用电铜出装机组的技术模式,而是需要另辟蹊径。还对新型电镍出装机组设计的技术路线进行了总结。

“1+1”宽幅铝带热轧机组开发与应用

随着铝合金在航空航天、汽车制造、建筑工程、船舶工业和化工领域的广泛应用,市场对高性能、超大规格铝板带材的需求显著增加。在此背景下,开发具有自主知识产权的“1+1”宽幅铝带热轧机组已成为提升我国铝加工装备制造水平的迫切需求。基于此本研究从机械设计制造专业的角度出发,结合多台铝板带热轧机组的设计与调试经验,详细阐述了3300/2800双机架宽幅铝带热轧机组的开发与应用,进而为高性能宽幅铝板带热轧机组的进一步优化设计和国产化提供理论依据和技术支持。

新风空调一体机在夏热冬冷地区超低能耗建筑中的应用

被动式超低能耗建筑具有高能效、高舒适性的特点,已成为助力实现“双碳”目标的重要举措。夏热冬冷地区夏季高温炎热,冬季阴冷潮湿,新风空调一体机能满足该地区供暖、供冷、通风与除湿等多种需求。以湖南省株洲市某被动式超低能耗建筑项目为例,详细阐述了新风空调一体机在该类项目中的设计与应用,并对其室内热环境和能源消耗进行了监测与分析。研究结果可为相关被动式超低能耗建筑项目的发展提供参考。

VVER核电机组热腿权重平均温度修正方法研究

针对VVER核电机组一回路热平衡功率计算偏差较大的问题,基于堆内构件三维数值模拟,开展热腿平均温度修正方法研究。提出以特定温度范围内的质量流量份额为权重系数,分析多种运行工况下权重系数的变化规律,建立了一套简化的热腿权重平均温度修正方法,结果表明热腿温度的计算值与机组实际运行时监测的热电阻测量值符合较好。所提出的修正方法有效、可靠,提高了热腿平均温度的准确性,改善了一回路热平衡功率计算偏差。

超超临界1030MW汽轮机转子振动大故障诊断及处理

针对一台综合改造后的1030MW汽轮发电机组在调试期间出现的振动故障,进行了诊断分析及处理工作。通过对启动过程中采集的频谱图、趋势图的分析,结合轴封体温度和低压缸减温水温度等运行参数变化情况发现:转子热弯曲和动静碰摩相互作用是本次转子振动大的主要原因,而转子质量不平衡是次要原因。并且,给出了解决振动的具体措施,不仅对低压缸排汽减温水喷头和轴封供汽管道进行了相应处理,同时还调整了转子的轴系平衡状态。这为今后此类改造机型启动阶段的振动故障处理提供了参考和借鉴。

船用给水机组凝水泵出口压力异常故障分析与排除

凝水泵是蒸汽动力船舶汽轮给水机组的重要组成部分,文章针对某船因增压泵内高温除氧水泄漏至凝水泵导致凝水泵汽蚀、给水机组热态切换时不能建立出口压力的故障案例,对故障排查过程进行了总结,为同类设备的故障排除提供了经验借鉴。

铁水预处理高效脱硫工艺

随着我国钢铁行业的发展,对钢中硫含量的要求越来越严格,一般要求钢中[S]的质量分数不大于0.02%,而一些对硫含量要求更为严格的钢种,则要求成品中硫含量小于0.005%。为了进一步提升铁水脱硫能力、降低铁水消耗,本文分析了KR预处理工艺过程中铁水温度、脱硫剂单耗、初始硫含量、搅拌时间对脱硫率的影响,针对KR工艺优化前存在的问题进行了分析,基于热力学平衡计算,建立了适宜的炉渣碱度、FeO以及温度的控制方式,更有利于获得碱度合适、流动性较好的炉渣,优化了渣钢反应的动力学条件。通过工艺优化,基于不同的铁水条件,调整装入量在78~80 t、优化搅拌头转速、搅拌时间以及搅拌深度,KR脱硫剂单耗为0.123 kg/(t·s),下降了13.38%,平均搅拌时间缩短了1.04 min,脱硫剂消耗减少了2.58 kg/t,吨钢脱硫渣量减少了1.97 kg/t,全天最高脱硫包数78包,全月有9次单班KR脱硫完成27炉,KR各项工艺指标均得到改善,形成了高效低成本KR冶炼工艺,降低了冶炼过程渣料消耗量,减少了冶炼成本,实现了KR高效低成本脱硫。

锅炉冷风加热系统方案综合对比分析

为探究避免锅炉空气预热器腐蚀的更优系统,以江苏某660 MW超超临界燃煤机组为应用对象,对比了目前实际运行中常用的3种系统,即热风再循环联合低温省煤器系统、蒸汽暖风器联合低温省煤器系统、水媒暖风器联合低温省煤器系统,分别从结构、性能和经济性方面考虑,选出最适合机组的系统。结果表明:在冬季工况下,水媒暖风器联合低温省煤器系统运行的可靠性较好、可调性较好、节煤量最大、投资回收期最短,综合性能最佳。

铸机热调宽配套定宽压力机工艺应用的节能效果研究

针对广西钢铁集团230 mm×1650 mm双流板坯在线热调宽功能和1780 mm热连轧机组定宽压力机减宽功能互相耦合下节能效果进行研究。研究发现,铸机热调宽配合压力定宽机工艺应用在2023年8个月的时间里有效节能约17561.5 MWh,约减少5699 t二氧化碳的排放。

夏热冬暖地区双热泵型泳池专用空调机组的适用性分析

为了验证双热泵型泳池专用空调机组在夏热冬暖地区的适用性,通过热湿负荷及空气处理过程计算,对福州市某游泳馆全年热湿负荷特征进行分析,结果表明:采用双热泵型泳池专用空调机组,可以较好地解决冬季供热不足的问题,冬季及室外含湿量较低的过渡季节,通过控制新风比使两套制冷循环均转化为制热循环时,机组提供的热量不仅可以满足空调系统所需的热量,还有富余的热量给池水加热,显著减少辅助热源的容量,减少电耗。

芳烃联合装置低温热回收技术研究

通过对现阶段芳烃装置低温余热的利用措施进行分析,指出芳烃装置低温热余热利用的技术难点;以某炼油厂的芳烃装置为例,详细分析和计算该装置的低温热现状,并以C_6、C_7烃类为内取热介质,为该装置设计了内、外双低温热换热系统,充分回收芳烃装置的有效低温热41 MW,通过该设计,有望将芳烃装置的能耗降低10%~15%。该技术充分克服芳烃装置操作压力低的工艺难点,为芳烃装置的抽余液塔、抽出液塔、成品塔等的低温余热有效回收利用提供新途径、新工艺。